炭素還元剤による鉄鉱石の溶融還元

抄録

The reduction reaction of iron oxide in molten state at 1 500°C and 1 400°C was investigated. By using an X-ray transmission apparatus, the behaviour of molten iron ore was observed continuously. MBR ore was reduced with graphite crucible or carbon in molten iron at 1 500°C and 1 400°C. In the case of reduction in graphite crucible at 1 500°C, the ore melted down until about 60 sec and the sample formed a flat liquid drop until the degree of reduction reached to 30%. As the reduction degree exceeded 30%, the molten iron oxide was expanded by the evolution of gas bubbles. As the degree of reduction exceeded 60%, drops of metallic iron were formed at the surface of molten iron oxide in contact with the wall of graphite crucible. The time change of reduction rate corresponded to the time change of expansion height of molten iron oxide. The area of interface between the molten iron oxide and graphite was estimated as the sum of the area of bottom and side wall of crucible. In the case of using a crucible, the bottom of which is graphite and side wall of which is alumina, the reduction rate obtained was 0.08 g-Oxygen/cm² min.